The disclosed embodiments pertain to a crumb made of 20 to 100 wt % of para phenylene terephthalamide pulp.
Products made of aramid are known.
In EP 0 191 127 a cake of synthetic fibrids is disclosed whereby the cake may comprise m-phenylene-terephthalamide. In the manufacturing process a slurry is pressed for hydroextraction and to form a plate-like cake. This cake is pulverized to form granules or flakes. The granules or flakes are pressed again to obtain a solid plate-like cake.
In JP 1097293 a method for producing a cake is disclosed, whereby an aramid fibrid slurry is compressed and the compressed product is crushed. The mentioned document has no indication of which kind of aramid is used.
In JP 2012197206 a slurry—containing also a small content of aramid fiber—is dehydrated for forming a raw plate.
US 2009/0101295 discloses a process for making pulp by using polypyridobisimidazole fibers. After a slurry is dewatered the obtained filter cake is wound up on rolls.
In US 2009/0029885 a process for making meta- and para-aramid pulp for use as reinforcement material is disclosed. The used slurry is dewatered and can be packed or wound up on rolls.
None of the mentioned products is made of para phenylene terephthalamide pulp (PPTA pulp) only. In addition, none of the references teach a method for producing a crumb being asymmetric.